Operation; Operation Range; Operating The System; About Operating The System - Daikin VRV IV+ RYYQ12U7Y1B Series Installer And User Manual

CAUTION
Do NOT operate the system when using a room
fumigation-type insecticide. Chemicals could collect in the
unit, and endanger the health of people who are
hypersensitive to chemicals.
NOTICE
Be sure to turn on the power 6 hours before operation in
order to have power running to the crankcase heater and
to protect the compressor.
This operation manual is for the following systems with standard
control. Before initiating operation, contact your dealer for the
operation that corresponds to your system type and mark. If your
installation has a customised control system, ask your dealer for the
operation that corresponds to your system.
Operation modes (depending on indoor unit type):
▪ Heating and cooling (air to air).
▪ Fan only operation (air to air).
▪ Heating and cooling (air to water).
Dedicated functions exist depending on the type of indoor unit, refer
to dedicated installation/operation manual for more information.
16

Operation

16.1

Operation range

Use the system in the following temperature and humidity ranges for
safe and effective operation.
Outdoor temperature
Indoor temperature
14~25°C WB
Indoor humidity
(a) To avoid condensation and water dripping out of the unit. If
the temperature or the humidity is beyond these conditions,
safety devices may be put in action and the air conditioner
may not operate.
Above operation range is only valid in case direct expansion indoor
units are connected to the VRV IV system.
Special operation ranges are valid in case of using Hydrobox units or
AHU. They can be found in the installation/operation manual of the
dedicated unit. Latest information can be found in the technical
engineering data.
16.2

Operating the system

16.2.1

About operating the system

▪ Operation procedure varies according to the combination of
outdoor unit and user interface.
▪ To protect the unit, turn on the main power switch 6 hours before
operation.
▪ If the main power supply is turned off during operation, operation
will restart automatically after the power turns back on again.
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1 – 2018.09
Cooling Heating
–5~43°C DB –20~21°C DB
–20~15.5°C WB
21~32°C DB 15~27°C DB
(a)
≤80%
16.2.2 About cooling, heating, fan only, and
automatic operation
▪ Changeover cannot be made with a user interface whose display
shows "change-over under centralised control" (refer to
installation and operation manual of the user interface).
▪ When the display "change-over under centralised control"
flashes, refer to "16.5.1 About setting the master user
interface" on page 63.
▪ The fan may keep on running for about 1 minute after the heating
operation stops.
▪ The air flow rate may adjust itself depending on the room
temperature or the fan may stop immediately. This is not a
malfunction.
16.2.3

About the heating operation

It may take longer to reach the set temperature for general heating
operation than for cooling operation.
The following operation is performed in order to prevent the heating
capacity from dropping or cold air from blowing.
Defrost operation
In heating operation, freezing of the outdoor unit's air cooled coil
increases over time, restricting the energy transfer to the outdoor
unit's coil. Heating capability decreases and the system needs to go
into defrost operation to be able to remove frost from the outdoor
unit's coil. During defrost operation the heating capacity on the
indoor unit side will temporarily drop until defrosting is completed.
After defrosting, the unit will regain its full heating capacity.
If
RYYQ or RYMQ The indoor unit will continue heating
outdoor unit is operation at a reduced level during defrost
installed operation. It will guarantee a decent comfort
level indoor. A heat storage element in the
outdoor unit will provide the energy to de-
ice the outdoor unit's air cooled coil during
defrost operation.
RXYQ outdoor unit is The indoor unit will stop fan operation, the
installed refrigerant cycle will reverse and energy
from inside the building will be used to
defrost the outdoor unit coil.
The indoor unit will indicate defrost operation on the display
Hot start
In order to prevent cold air from blowing out of an indoor unit at the
start of heating operation, the indoor fan is automatically stopped.
The display of the user interface shows
time before the fan starts. This is not a malfunction.
INFORMATION
▪ The heating capacity
temperature falls. If this happens, use another heating
device together with the unit. (When using together with
appliances that produce open fire, ventilate the room
constantly). Do not place appliances that produce open
fire in places exposed to the air flow from the unit or
under the unit.
▪ It takes some time to heat up the room from the time
the unit is started since the unit uses a hot-air
circulating system to heat the entire room.
▪ If the hot air rises to the ceiling, leaving the area above
the floor cold, we recommend that you use the
circulator (the indoor fan for circulating air). Contact
your dealer for details.
16 Operation
Then
.
. It may take some
drops when the outside
Installer and user reference guide
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